| 摘要 |
This rolled steel sheet contains specific quantities of C, Si, Mn, P, S, Al and N, with the remainder being made up of unavoidable impurities. The steel structure has a specific volume fraction of ferrite, volume fraction of bainitic ferrite, volume fraction of residue γ, volume fraction of tempered martensite and volume fraction of martensite, the average particle size of the circle equivalent diameter of cementite present in the tempered martensite does not exceed 200nm, and the number density is at least 10/μm2. |
